Also called: backend memory contexts view, memory context introspection
In plain English
pg_backend_memory_contexts is a system view (PostgreSQL 14+) listing every memory context in the current backend — name, parent, depth level, and total/used/free bytes. It exposes the live context tree so you can see exactly where a backend’s memory is going.
Why it matters
It turns “this connection is using 2 GB” into “its CacheMemoryContext is 1.8 GB.” Paired with pg_log_backend_memory_contexts(pid), which dumps another backend’s contexts to the server log, it is the primary tool for diagnosing per-backend memory bloat.